Ments



March 19, 1929. F. DREXLER GYROSCOPIC DEVICE 3- Sheets-Sheet Filed June 12. 1919 INV/YTO)? Fm/vz DREXLE/P @ZZWQM March 19, 1929. F, DREXLER Y 1,706,201

GYROSCOPIC DEVICE Filed June 12. 1919 s Sheets-Sheet 2 March 19, 1929. I DREXLER 1,706,201

GYROSGOPIC DEVICE Filed June 12. 1919 s Sheets-Sheet 3 W/7/VE55 Mum Patented Mar. 19, 1929.

VUNITEDSTATESO PATENT OFFICE.

FRANZ DREXLER, OF BERLIN-FRI.EDENAU, GEE-MANY, ASSIG'NOR, BY MESNE ASSIGN- MENTS, TO PIONEER INSTRUMENT COMPANY, INCORPORATED, OIL BROOKLYN, NEW

YORK, A CORPORATION OF NEW YORK.

GYROSCOPIC DEVICE.

Application filed June 12, 1919, Serial No. 303,808, and in Germany October 17, 1917.

(GRANTED UNDER THE PROVISIONS OF THE AC1 OF MARCH 3, 1921, 41 STAT. L, 1313.)

The object of this invention is to provide a gyroscopic device for indicating the horizontal turn of a movable dirigible object. The present gyroscopic device is mainly in tended for vehicles, especially aeroplanes, for indicating thedirection and rate oi turn of the same around a normally vertical axis.

According to this invention the horizontal turn to be measured is transferred to a support on which a gyroscope is so mounted that the gyroscope axle may swing in a plane of said support parallel to the normally vertical axis thereof. Resilient means, tending to keep the gyroscope axle in a definite angular,

preferably rectangular,position relative to said support axis, are operatively associated with the gyroscope axle and with the support lVhen the dirigible object makes a horizontal turn, the aforementioned plane in which the gyroscope axle may swing, is turned correspondingly. Aceording'to the well-known law of physics of the gyroscope, the gyroscope reacts upon the angular displacement of its axis by tending to swing within the plane mentioned. This tendency is counteracted by the resilient means so that the gyroscope axle is deflected to a certain extent dependent upon the rate of the turn. The direction of the deflection, which is indicated by suitable means, shows the direction of turn.

Another object of the invention is a turn indicator for a dirigible object whica is adapted to make turns in a verticalv plane and to be subjected to forces tending to impart to the same swinging oscillations in. said plane as well as swinging oscillations in a plane rectangular to the direction of travel.

A further object of the invention is a gyroscopic device for aeroplanes, which. indicates the correct degree of banking, i. e. the lateral inclination in turns, and which is particularly adapted for that type of aeroplane which requires a degree of banking which cannot be determined by the usual pendulum device or clinometer.

If the diri'gible object, the turn o'l which is to be measured is adapted to make turns In the accompanying drawings I have represented several examples of apparatus embodying my invention.

lllig. l a perspective view ol a gvroscopic device, equipped with two penduluins and suitable for use with vel1icles, especially aeroplanes, it cing assumed that the veh icleor is travelin forward in a straight line.

i 2 shows in perspective the same device as 1, during a horizontal turn or bankmg of the vehicle.

F 3 is a perspective view oi? a gyroscopic dcviceequippcd with a pendulum, and adaptpd to indicate the required degree of bank- 111g.

ll ig. 4L shows in perspective a further form gyroscopic device constructed according to of my i mention, in which the vehicle is assumed to be traveling forward. This form has no pendulum but has a special kind of resilient restraining or limiting device restricting or checking the swing about one oi the axes of the apparatus, and Fig. 5 illustrates another form of my invention.

There is a special demand in the case of vehicles of the above-mentioned kind for measuring the horizontal turn of the vehicle, that is to say, the horizontal deviation of the vehicle from the straight course. With many vehicles, esoecially aeroplanes or aircraft in general, it is further important to provide means enabling the operator controlhug the aeroplane, to counteract forces tending to impart to the aeroplane swinging oscillations transverse to the direction of travel. Such oscillations are liable to disturb the function ot' the turn indicator.

Fig. 1 shows a form of the gyroscopic device which is particularly adapted for aeroplanes. ji. spinning top or gyroscope 1 having an axle 2 is mounted in a box-shaped suijiport 5 in such a manner that the axle 2 may swing in a plane parallel to the axis 1?. 15 of aid support. This axis has a vertical posi is to say, during travel in a straight horizontal line. Preferably, the axle 2 is rotatably mounted within a ring or frame 3, which swings around an axis l 4 within the boxshaped support 0. The axis 4-4E is angularly, n'eferably rectangularly disposed with on under normalconditions, that respect to the axis 1515 of the support. Two springs 6-6 serve for connecting the frame 3 resiliently with the bottom of the support 5, thereby forming resilient means tending to keep the axle 2 in a definite angular, preferably rectangular, position, to the axis 1515. The support is fixed upon the dirigible object or vehicle. The axle a of the ring shaped frame 3 carries a pointer 7, whose position may be read off at two scales 8-8 fixed to t-hesupport. In that v a 1 the pointer 7 indicates in which direction and at which rate the axle 2 is deflected from its normal position. A pendulum 9 is mounted upon the front of the box 5 so as to swing around the axle 10 transversely to the direction of travel, and in front of the scale ll. As the front of the box 5 forms a dial which carries thescales or indicating marks 88 cooperating with the pointer or indicator 7, and the scale 11 cooperating with the pendulum 9, the indicator 7 and the pendulum 9 are thus coordinated with the same dial andare in the same field of view to be observed simultaneously. Another pendulum 12 is mounted on the sidewall of the box 5 and swings perpendicularly to the former pendulum around the axle 13 and in front of the scale 14. 1

The operation of the device is as follows:

When the aeroplane changes its course so as'to make a horizontal turn, as shown by the arrow in Fig. 2, the axle 2 is correspondingly turned, when seen in plan view, and the gyroscope reacts upon such a turn by a precession HIOVQHIGDttGDCliH to swing, rectangularly to the plane of the turn, with a force which depends upon the rate of the turn. Therefore, the gyroscope deflects its frame 3 swinging the same about the pivots 4. As the resisting force of the springs 6 increases with the deflection of the frame, the gyroscope assumes a position, the inclination of which relative to the support 5 indicates the rate of turn and is shown by the pointer 7 on the scales 8.

It may be assumed that the aeroplane takes a straight horizontal course as represented by the arrow in Fig. 1. Consequently, the absolute direction of the axle 2 remains unchanged and the pointer 7 points to the centers of the scales 8. When now, under the influence of irregular wind currents, the one wing of the aeroplane is lifted and the other wing is depressed, and if the operator is prevented by fog or cloudsfrom recognizing this tilting of the aeroplane with respect to the horizon, the one spring exerts a downward pull'on the frame 3 while the other spring is relieved. Consequently, the springs tend to swing the axle 2. It is a well-known fact, that the gyroscope tends to resist such a displacement of its axle and to retain the absolute direction of the same, though it tends to swing rectangnlarly to the exerted pull if it is free to do so. Therefore, the pointer retains its absolute direction for some time until the resistance of the gyroscope is overcome by the continuing action of the springs. Since the scales 8, however, are displaced corresponding to the assumed tilting of the aeroplane, the pointer "Z does not point any more to the centers of the scales but gives a positive indication, which is not due to any turn. After some time only, when the resist ance of the gyroscope overcome as above described, the pointer returns to its .zcro position. Vihen the influence of the irregular wind current which caused the tilting, has ceased, the aeroplane, under normal conditions, assumes automatically again its normal position. Now, the gyroscope resi s for some time a readjustment int. its or nal horizontal position and, therefore, can .1 another deflection of the pointer T with respect to the scales 8.

From this consideration will be seen that swinging oscillations of the aeroplane in a plane transverse to its direction of travel, cause deflection of the pointer T which are not due to any horizontal turn and, consequently, result in a wrong indication.

Provision mustbe made, therefore. for enabling the operator of the aeroplane to counteract the described tiltings or oscillations whether or not he can see the horizon. In the represented embodiment. these provh sions comprise the pendulum 9, which gives indication of the described swinging: oscil lation. The operator has to k the acre-- plane in a position in which the pendulum 9 assumes a definite position with respect to the scale 11. Then the pointer i" gives a correct indication. The pendulum 9 and the pointer '7 are arranged in the same field of view to be simultaneously observed by the operator, L

The pendulum l2 indic: any inclination of the ion aeroplane.

It is well known that during a horizontal turn an aeroplane haste be kept laterally inclined to a certain d gree. This inclination, called banking, is dependent: on the rate of turn.

In some types of aeroplanes, the correct degree of banking may be obtained by keeping the aeroplane in a position in which a pendulum arranged thereon, e. the pendulum 9 in Figs. 1 and 2, assumes its normal central position, that is, the position which it assumes on the straight course.

In certain types of aeroplanes, however. the degree of banking must be smal er or greater by an amount which is dependent on the rate of turn, because the two wines have a different speed and, therefore, a different lifting force. 7

In Fig. 3 a gyroscopic device is shown, which indicates the degree of banking on th cale ,adinal axis of the quired for such types of aeroplanes. This device performs in addition the same function as the device shown in Figs. 1 and 2.

A spinning top 16 having its axis at 17 rotates within a ring 18 which is mounted by means of two pivots 1919 upon two sup ports 20-20. The top or gyroscope 16 may be rotated in any suitable manner, for instance by means of an electromotor indicated at 16 (Fig. A pin 21 fixed on the ring 18 projects into a slot of a pointer 22 pivotally mounted upon the axle 23 and moving in front of a scale 24. Two springs 25-25 whose fixed points are arranged upon supporting frame 20 (Fig. will limit or oppose the swinging of the ring 18 around the axle 19-19. A scale 26 is operatively connected to the frame or ring 18 so as to be dis- 7 placed by the deflection of the ring. In the represented embodiment, the scale is rigidly mounted on the front pivot 19. Furthermore a pendulum 27 is suspended from this pivot so as to swing with respect to, and to point on,

' the scale 26.

If, due to a horizontal turn of the aeroplane, the gyroscopic device swings about the axis 28-28, the spinning top will exert a torque around the axis 19-19 which will be received by the springs 2525, so that the top will undergo a deflection in the direction of the torque. This deflection is indicated by the pointer 22 on the scale 24 in any desired ratio of magnification. At the same time the scale 26 will be turned through a definite angle relatively to the vehicle, said angle being dependent upon the deflection of the frame 18 of the spinning top as shown in the particular arrangement represented in the drawing.

The operator has to impart to the aeroplane such a lateral inclination, that the pendulum 27 points always to the center of the scale 26. If the speed of rotation of the gyroscope, as well as the strength of the springs 25, is properly designed, with respect to the qualities of stability of the aeroplane, the correct degree of banking is always obtained in this way, whatever the rate of horizontal turn may be.

A special advantage of the embodiment shown in Figs. 1, 2 and 3 for the use in aeroplanes results from the fact that the gyroscope axle normally assumes a horizontal position which is transverse to the direction of travel. Due to this position the gyroscope remains substantially unalfected by turns of the aeroplane in a vertical plane and by oscillations in that plane which might be produced by irregular air current.

Ifsuch oscillations of a considerable extent and turns in a vertical plane are not in question, and if swinging oscillations in a plane rectangular to the direction of travel cannot be counteracted by the operator, as is the case with a ship, the gyroscopic turn indicator shown in Fig. l is especially well suited. In this construction the gyroscope axle is longitudinally positioned to the direction of travel.

A frame 30 is movably mounted within a support 29 upon pivots Ell-31. A spinning top 32 is rotatably mounted upon the axle 33 within said frame 30. An arm 3 1 of the frame 30 co-operates with the lever 35 which actuatos the pointer 37 through a resilient connecting link 36, said pointer being rotatably mounted in the fixed bearing 38. Two springs 3939 attached with their outer ends to upwardly projecting arms of the support 29 and with their inner ends to the pointer 37, tend to keep the pointer 37 in the center of the scale 40.

Assuming that the vehicle, such as ship be heavily rocking or oscillating about its longitudinal axis and in a smaller degree around its transverse axis, it is of fundamental importance to arrange the axis of the spinning top parallel to the axis of the larg est oscillations, that is, in the direction of the travel. The reason for this is that all oscillations of the support 29, which take place around an axis parallel to thatof the spinning top, do not exert the above explained disturbing influence upon the gyroscope, while movements around the axis 3l31 will disturb the latter. Through the resilient connecting link 36 vibrations of the vehicle, which could cause heavy swinging of the pointer 37, are rendered harmless. By this a more exact indication is attained because the inaccuracies which are inherent to the transmitting elements for the deflection of the gyroscope do not come into action.

The deflection of the gyroscopic device may be damped in a suitable manner. In Fig. 1, a rod 46 is hinged to the frame 3 and a rod 17 is hinged to the support 5. Both the rods are connected by a dash pot 45 of welhknown construction. The dash pot permitsa mutual reciprocating movement of the rods 16 and 17 and damps this movement.

Instead of the pendulums shown in the fig ures, any desired pendulum means or clinometers showing the apparent direction of gravity maybe employed.

I claim:

1. A gyroscopic device for indicating the turning of a movable object about an axis, comprising a support fixed to said movable object, a frame rotatably arranged on said support by pivots, a scale rigidly mounted on one of said pivots to rotate with the frame,

a pendulum freely movable on said pivot and having indicating means reading on said sgale, a gyroscope rotatably arranged in said frame, the axes of said frame and gyroscope being at right-angles to one another, springs connecting said frame with said support to resist the movement of said frame, a pointer arranged on said support, there being a slot lUl) in said pointer, a pin arranged on the f 'ame, said pin projecting into said slot, and a scale for reading off the movement of said pointer.

A gyroscopic device for indicating the correct degree of banking of aeroplanes of the type set forth the specification, comprising a support fixed to the aeroplane, a frame rotatably mounted on said support, the axis of said frame beii'ig anyularly disposed with respect. to the normally vertical axis of said support, a gyroscope rotatably mounted on said frame, the axis ofsaid gyroscope being at a right angle to said frame axis, resilient means operatively associated with said frame and with said support, and

tending to influence the frame to keep the gyroscope axis in a definite angular position relative to said vertical support axis, a scale operatively connected to said frame so as to be displaced by the deflection thereof from the aforementioned definite position, and a pendulum device associated with aid support and adapted to, swing with respect to, and to point on said scale, so that the operator of the aeroplane may hold the same, during a turn, on such av bank in which a dehnite point of said scale coincides with the position of said pendulum device.

3. A gyroscopic device for indicating the horizontal turn of an aeroplane, comprising a support fixed to saidaeroplane and provided with a dial, a gyroscope, a frame for mounting the same in said support for precession in a plane parallel to the normally vertical axis of said support, resilient means opera-tively associated with said frame and with said support, and tending to influence the frame to keep the gyroscope axis in a dei'inite angular position relative to sax support axis, and an indicator mounted to swing in front. of said dial operatively connected with said frame to move in unison therewith, for indicating on said dial the precession of said yroscope axis from the aforementioned definlte position, whereby the direction and the rate of turn is indicated, and pendulum means swinging transversely to the direction of travel and arranged in the same field of view is said indicator to be observed by the driver operating the aeroplane sinmltancously with said indicator.

-l-. A gyroscopic device as forth in claim 8 in which the resilient means are formed by a spring tending, with a force which increases in a definite position relative to said support, which position is normally horizontal, so that the said gvroscope axis tends to assume, horizoi'ital position transverse to the direction of travel a nd, thm'cforc, remains substantia unaffected by vertical turns, and an indicator operztively connected to said frame to move in unison therewith, a 6 all with indicating marks fixed to said support. in a plane adjacent to the plane of movement of said indicator for indicating the precession of said gyroscope from the afore-mentioned definite position, whereby the direction and the rate of turn is indicated, and pendulum means swinging transversely to the direction of travel and arranged in the same field of view as said in dicator to be observed by the driver operating the aeroplane simultaneously with said indicator.

lin. testimony whereof I have hereunto set my signature.

FRANZ DREXLER. 

